Structural Pattern in Central Uplifts of Cryptoexplosion Structures as Typified by Sierra Madera

Abstract

The pattern of deformation in central uplifts of Sierra Madera and other well-known cryptoexplosion structures indicates that inward as well as upward movement of strata formed the uplifts. This kind of movement is incompatible with structures not of impact origin with which they have been compared. The structural style of cryptoexplosion structures, together with features that suggest shock deformation, supports the belief that they are the eroded roots of impact craters.

Mousso structure: A deeply eroded, medium-sized, complex impact crater in northern Chad?

“…However, the detailed structural investigation of the central uplift of the Upheaval Dome impact structure, Utah, USA, by Kenkmann et al (2005) shows an analogous structural arrangement. A similar deformation pattern has also been reported from the central uplifts of the Sierra Madera impact structure, Texas, USA (Wilshire and Howard, 1968) and the Gosses Bluff impact structure, central Australia (Milton et al, 1996;Scherler et al, 2006). The central uplifts of the Spider, Upheaval Dome, and Gosses Bluff impact structures are characterised by bilateral symmetry in their complex fault systems and show central anticlines as common structural features (Milton et al, 1972;Abels, 2005;Kenkmann et al, 2005).…”

“…From remote sensing, the Mousso structure lacks evidence of a diapiric origin. Diapiric phenomena, even in an eroded state, are known to be characterised by structural features related to crustal thinning and faulting, and typically exhibit radial faults in drag zones adjacent to the diapirs (Wilshire and Howard, 1968;Alsop et al, 2000;Yamada et al, 2005). In contrast, no radial lineations appear but rather a circular, concentric fault pattern can be observed on satellite images of the Mousso structure.…”

“…The central uplifts of the Spider, Upheaval Dome, and Gosses Bluff impact structures are characterised by bilateral symmetry in their complex fault systems and show central anticlines as common structural features (Milton et al, 1972;Abels, 2005;Kenkmann et al, 2005). The central uplift of the Sierra Madera impact structure exhibits several NW-SE trending central anticlines (see Wilshire and Howard, 1968). The establishment of bilateral symmetry within a central uplift has been explained by the oblique incidence of the impactor and by the collapse and incorporation of material from the uprange into the rising central uplift, which leads to asymmetric deformation inside the uplift and the generation of imbricated slices (Milton et al, 1972;Abels, 2005;Kenkmann et al, 2005).…”

Observations at terrestrial impact structures: Their utility in constraining crater formation

“…These basic morphological elements are, generally, common to complex impact structures on the terrestrial planets. The rocks present at the center of terrestrial complex impact structures have been uplifted from depth and display increasing depth of origin and age as the center is approached (e.g., Gosses Bluff, Australia [Milton et al 1972]; Red Wing, USA [Brenan et al 1975]; Sierra Madera, USA [Wilshire and Howard 1968]). The observed amount of structural uplift (SU; Fig.…”

Rietveld analysis of X‐ray powder diffraction patterns as a potential tool for the identification of impact‐deformed carbonate rocks

“…The Sierra Madera impact structure, located near Fort Stockton, Texas, is a well-exposed, eroded remnant of a complex, 12 km diameter impact structure (Eggleton and Shoemaker 1961;Wilshire and Howard 1968;Howard et al 1972;Wilshire et al 1972). The central uplift is composed of steeply dipping, folded, and faulted Upper Permian strata (Fig.…”